1. Field of the Invention
The present disclosure relates to a light emitting device package containing a phosphor and a scattering agent and a method of fabricating the same.
2. Description of the Related Art
A backlight unit emits light on a rear surface of a liquid crystal panel so the user can view an image. In more detail, the liquid crystal panel does not emit light itself and thus light is uniformly emitted on the rear surface of the liquid crystal panel so the user can visually recognize an image displayed on the display unit.
The backlight unit uses a light source such as a light emitting device (light emitting diode (LED)) or a cold cathode fluorescent lamp (CCFL). The light emitting device has a lot of advantages compared to the CCFL because of lower power consumption, a long lifespan as well as easy fabrication of a small sized device. The light emitting device in the backlight unit is implemented in package form in which an encapsulant covers the light emitting device. Further, the light emitting device package may be a blue light emitting device package or a package containing a small amount of green phosphor or red phosphor.
In addition, efforts for improving the efficiency of the light emitting device itself as well as improving the light extraction efficiency of the light emitting device package have been performed. For example, in order to improve the light extraction efficiency in the light emitting device package, an uneven surface (forming a geometric structure or optical crystal structure) may be formed or a scattering agent/phosphor may be coated to enhance the light extraction efficiency. For a blue light emitting device package, the extraction efficiency has been improved by dispersing a scattering agent instead of containing no phosphor. However, such methods have a drawback of insufficient improvement in light extraction efficiency since photons generated from the light emitting device are unable to sufficiently escape from the encapsulant to an air space.
In general, a refraction index on each portion of the light emitting device package increases in the order of the light emitting device, the encapsulant, and the air space, and as a result, the package has a structure in which the escape of light or photons into the air space is not easy due to a total reflection phenomenon.